This is the chainplate fitting below the furler drum. The chainplate holes are 8mm, so it won't fit directly to the 1/4" holes in the deck tang. I've therefore used a 6mm toggle with one hole drilled out to 8mm as an adaptor.

The bottom of the forestay is fitted with an 8mm roller-swaged termination which is pinned into the chainplate. Forestay adjustment is made by changing which chainplate hole is used.